1. Field of the Invention
The present invention relates to a time information management system, and more particularly to a time information management system that uses public standard time information and which causes the timekeeping condition of one or more clock means existing within a pre-established area to always coincide with this public standard time information.
2. Background of the Invention
In the past, in a system for example such as a master-slave clock system, one known method of aligning the time information of clocks within one system to the same time information, such as noted in Japanese Unexamined Patent Publication (KOKAI) No. 62-276488, is that in which a plurality of transmission lines are used to connect the master clock to a plurality of slave clocks and in which, in the time-setting mode, the master clock sends to the slave clocks time information for use after the time setting, using digital time-division multiplexing transmission, so that transmission is made to each of the slave clocks in sequential fashion, thereby setting the time information of clocks in one system to one and the same time information.
Recently, other known methods include a method of making a connection to a time displaying means that has a telephone control apparatus by using a telephone line, and using standard time information, such as JJY time information, that is sent via this telephone line to correct the time information of the time displaying means, a method of receiving either time information that is included in radio information that is transmitted from a man-made satellite or receiving standard time information that is included in ground-based television or radio broadcasts to either automatically or manually correct the time information that is currently being displayed by a prescribed timekeeping display means.
However, in these methods of the past, such as with the time information correction method that is noted in Japanese Unexamined Patent Publication (KOKAI) No. 62-276488, because the time information that is kept by the master clock is the reference time information, in the case in which there is an error in the time information kept by the master clock with respect to standard time information, all the slave clocks connected thereto will have an error with respect to the standard time information, the result being that it was necessary to use some means to accurately correct the time information of the master clock.
In the latter described methods of time information correction, using the above-noted public standard time information it is possible in a single operation to correct the time of only one clock, so that in the case in which there is a plurality of clocks or timekeeping means, it is necessary to execute the above-noted correction operation separately and repeatedly.
For this reason, with respect to a plurality of clocks or timekeeping means, the operation of correcting the currently displayed time information to coincide with the standard time information became complex and time consuming.
An object of the present invention is to provide a time information correction system which improves on the drawbacks of the prior art as noted above and, while having a simple configuration, causes the individual time information of one or more clocks existing within a prescribed area, or of a timekeeping means that forms an appropriate timer means to instantaneously coincide with the current standard time information.